Wireless communication systems have been widely spread as a data communication means because of their high convenience, for example, only few location restrictions as to where they are used. Examples of such wireless communication systems include a wireless communication system employing an infrastructure mode in the wireless LAN prescribed in IEEE 802.11 (see NPL 1). The spread of this wireless communication system has been accelerated because networks can be easily built with unspecified mobile terminals. Hereinafter, mobile terminals which perform wireless communication in the above-described wireless communication system will be referred to as “wireless LAN terminals.”
In the infrastructure mode, a wireless LAN terminal of a plurality of wireless LAN terminals serves as an access point. The wireless LAN terminal which serves as an access point (hereinafter, referred to as a “wireless access point terminal”) includes a wireless communication section which can individually perform wireless communication with a plurality of wireless LAN terminals. The wireless access point terminal connects the other wireless LAN terminals to a network individually using the wireless communication section. That is, the wireless access point terminal transfers data between each wireless LAN terminal and the network or other wireless LAN terminals.
In addition to the data transfer operation, the wireless access point terminal performs operations such as periodic transmission of a beacon signal and standby for data transmitted from the wireless LAN terminals in order to maintain connection with the wireless LAN terminals to the network. For this reason, the processing load and power consumption of the wireless access point terminal increase as the number of the wireless LAN terminals connected to the network (within the area served by the wireless access point terminal) increases. As described above, since the wireless LAN terminals are mobile terminals and thus are basically driven by batteries, power saving is preferred.
In this respect, PTL 1 discloses a technique for reducing the frequency of beacon transmission when there is no wireless LAN terminal within the area served by the wireless access point terminal (hereinafter, referred to as an “in-coverage terminal”), for example. According to this related art, it is possible to reduce power consumption of the wireless access point terminal when there is no in-coverage terminal.